This invention relates to apparatus for making holographic images of three-dimensional objects and, more particularly, to holographic recording apparatus which is portable and easy to use which makes it an especially useful tool in the teaching environment.
In the making of holographic pictures, it is of utmost importance to eliminate or substantially reduce all vibrational disturbances as well as air currents and temperature fluctuations which virtually destroy the holographic image when raised above a tolerable threshold. The prior art thus includes various vibration reduction techniques such as positioning the camera assembly elements within a bed of sand and weighing down the camera support table, typically with concrete.
An example of one such vibration reduction technique may be seen in U.S. Pat. No. 3,526,444 issued to Carcel et al on Sep. 1, 1970. Other vibration reduction techniques include an elaborate framework in which camera elements are mounted (U.S. Pat. No. 4,707,053 issued to Gurevich et al on Nov. 17, 1987) and embedding the optical system in a transparent molding material (U.S. Pat. No. 4,508,420 issued to Nishiwaki on Apr. 2, 1985).
In addition to vibrational stability, it is of course necessary that no light impinge upon the film during exposure other than the coherent light source beam which comprises the so-called "reference beam". The above requirements obviously pose of a definite challenge to teaching the holographic process to a group of students in the classroom. The present inventor realized the need for a holographic assembly which could be easily transported from classroom to classroom and allow a group of students to easily observe the apparatus and process and also make their own holographic pictures using the apparatus, all in a short period of time.
It is thus a principal object of the present invention to provide a holographic camera assembly which is compact and portable.
It is a further object to provide a holographic camera assembly having a light-tight, external housing providing an enclosure for the camera components such that a conventional "dark room" environment is not necessary during the holographing procedure.
It is another object to provide a holographic camera assembly which includes an easy to use control panel externally of the housing.
It is yet another object to provide a holographic camera assembly including a unique, light-tight film casing which permits the deposit and removal of the film and film casing in and out of the enclosure, respectively, thereby preventing destructive exposure of the film, means included to lift and lower the casing about the film during exposure within the housing.
It is still another object to provide a holographic camera assembly which includes simple yet effective techniques for substantially reducing the effects of vibration, temperature and air currents.
Other objects will in part be obvious and in part appear hereinafter.